I put in 100 gal fresh 75 gal grey 35 gal black . When we use state parks with no sewer hock up I would have liked to have had 100 gal grey? The black can last as long as 3 weeks with the proper additives if its just my wife and I. So put in a black and a grey tank would be my opinion dave

But I was curious how much larger the waste tanks should be than the fresh water tank. I assume you shouldn't plan on using public bathrooms (gas stations, tourist spots, etc) to prevent excess use of your own tanks?

But I was curious how much larger the waste tanks should be than the fresh water tank. I assume you shouldn't plan on using public bathrooms (gas stations, tourist spots, etc) to prevent excess use of your own tanks?

I figure my waste tank would need to be 10% to 20% larger than the fresh water tank for the waste tank to not get full before the water tank is empty.

The biggest issue for me is the waste tanks filling up when boondocking. When I am on the road there are usually plenty of places to empty the tank. We will use public restrooms when we stop for fuel or whatever, but not specifically to keep the tanks from filling up.

If you put the water heater in the same bay as the fresh/grey/black tanks, even tho it's insulated, there will be some heat given off that might just save you a broken water line if you're suddenly caught in a cold front. It does happen, even in FL. . .

Additionally, someone else mentioned this, but in the back bay is a lot closer to the head and kitchen sink than the old HVAC condenser compartment - thus less water waste potential, even with the recirculation feature.

If you stack your tanks, that will open up some additional space in the bay. Just make sure you've got sufficient support for the upper ones.

Not putting the water heater up front also allows you to use that compartment for your genset, or a couple of portable propane bottles (if you're planning on using propane for anything.)

Think nautical - sailors have been putting a quart in a pint pot for over 5,000 years. Our buses are simply land yachts!